1. Technical Field
The present invention relates to a wireless communication device and a wireless communication system, which perform communication by sound packets.
2. Background Art
The communication quality of wireless communication is greatly affected by the electric field strength of a transmitted radio wave, the distance between devices, and the existence of an interference radio wave. To cope with this, for example, a technique described in a wireless telephone system of JP-T-2002-509387 is known.
The wireless telephone system of JP-T-2002-509387 as described above includes a base transceiver and a wireless handset for a fixed-size audio packet composed of a plurality of audio data samples and a plurality of error correction bits, and changes the relative numbers of the audio data samples and bits allocated to the error correction bits with respect to the packet construction of the subsequent audio packet by determining whether or not an error rate has been changed through monitoring of the quality of a digital link on a wireless channel.
That is, if the error rate is deteriorated, the wireless telephone system performs switching of the quality level from the highest quality level to an intermediate quality level or a low quality level through reduction of the data amount of the audio data sample included in a packet with a fixed size, and widens the distance range or gives a high tolerance to the interference radio wave through an increase of the data amount of the error correction bits.
Since the wireless telephone system described in JP-T-2002-509387 performs switching of the quality level from the highest quality level to the intermediate quality level or the low quality level due to the deterioration of the sound data rate in order to increase the data amount of the error correction bits when the error rate is heightened due to the deterioration of the communication environment, it is considered that the sound quality is deteriorated.
However, it is hard for a user to use the wireless telephone system in which the sound quality is deteriorated to follow the deterioration of the communication environment. Accordingly, it is required to maintain the sound quality to some extent even if the communication environment is deteriorated.